Flame hardening apparatus



April-28, 1953 M. R. NELSON "ET AL FLAME HARDENING APPARATUS l0Sheets-Sheet 1 Filed Oct. 6, 1947 Fig... 1

I'gI ENTORS MANLEY NELSON BY RICHARD 5. $HEEHAN ATTORNEY April 8, 1953M. R. NELSON ETAL 2,636,725

FLAME HARDENING APPARATUS Filed Oct. ,6, 1947 10 Sheets-Sheet 2INVENTORS MANLEY R. NELSON BY RICHARD 8. SHEEHAN ATTORNEY April 1953 M.R. NELSON EIAL 2,636,725

FLAME HARDENING APPARATUS Filed 001:. 6, 1947 10 Sheets-Sheet 3INVENTORJ' MANLEY R. NELSON BY RICHARD 5. SHEEHA N ATTORNEY April 28,1953 M. R. NELSON ETAL FLAME HARDENING APPARATUS Filed 001:. 6, 1947 10Sheets-Sheet v4 B I I w v ,0, m

INVENTORS MANLEY R. NELSON RICHARD S. SHEE HAN 42 a. 2 Dfifl w ATTORNEYN SMA 5 5 W. n t Map. e w E H VI 6 M V N 5 M a MRS 9 l. V D 2 m m 0 5K,8 wmx/ m S o m m N l I.| NH b 23 m m. NQ R MR V: B

M R NELSON ET AL FLAME HARDENING APPARATUS April 28, 1953 Flled Oct 6,1947 April 1953 M. R. NELSON ETAL. 2,636,725

FLAME HARDENING APPARATUS Filed Oct. 6, 1947 10 Sheets-Sheet 6 MANLEY R.NELSON BY RICHARD 8. SHEEHAN A 7' TORNE Y April 28, 1953 M. R. NELSON ETAL FLAME HARDENING APPARATUS 10 Sheets-Sheet '7 Filed Oct. 6, 1947 FIG.

INVENTORS MAIVLE) R. NELSON BY mam/20 s. SHEEHAN /za n a ATTORNEY M. R.NELSON ET AL FLAME HARDENING APPARATUS April 28, 1953 10 Sheets-Sheet 8INVENTORS MANLEY R.NSEJE IFE% AN RICHARD S. H

A TTOR/VE Y Filed Oct. 6, 1947 N N m% w 9 T L E N 7 u WEE. m 6 m w n 3 Sm A 6 H? R S s. t 2 e 0 D m E R 4 w. M MR M R NELSON ETAL FLAMEHARDENING APPARATUS April 28, 1953 Filed Oct 6 1947 April 28, 1953 M. R.NELSON ET AL FLAME HARDENING APPARATUS l0 Sheets-Sheet 10 Filed 001;. 6,1947 INVENTOR. MANLEY R. N E LSON BY RICHARD S. SHEEHAN ATTORNEY.

Patented Apr. 28, 1 9 53 Manley R. and ltiehard sii's'lreehan, Denver,Colo.

asmicatiwoemtert, 19mgsssrsawam invention "relates to same rrardefimgand apparatus, and more particularly man as to a versal "flame hardeningmac ame hardening, a high tempsmwreaeae ihg 'flame, presentl ahcky-acetylene amass ut'iiized to heat selected surface portions of "ahardenable metal object tusualiy steel) 'to a "desi re'd depth and to atemperatsre above the critic'ai, so that upon cooling at a sufiicintiyrapiii 'ra te ahardened case is produced. Except in the case-orair-hardening steel, a quenching mediurh ,'ii'sua1-1 y water, directedagainst the heateasurrate to effect cooling at an appropriate fame;

fii freaie fou r general methods or application of heme hardening, thefirst and simplest being, spot heme" 'ng, int'zhi'ch a singi'e 'fiandeor g-rou o f fiames "5 need to a selected surface ps1 dn 'oi ast" I yjest until the area is lfeaited'to the 'e'qu-isit'eternperature anddepth, whereupo the name is removed "and t he quench 2th 'ed. a secondmethod, termed discontent ithainthe total area is employed, and eitherthe l fia me or the object, or iboth, are moved, such as toaansffro orby rotation, untn the totaharea is heated to the desired temperatureandfcl th, wuereupen the lia-me is movedaway or e'xti n guished gal 01the iuench. applied. The fliSCOYe tinuous method isiusedt in flamehardeningehj'ects sucha's rait endsgcranks'ha'ft bearings, valve faces,andttheiike, and also in the :spmnarden mg of small gears N a thiadmethod, termed ,fprogre'ssive, a

fiameuroragroup mT-fiames is used inuheatingisu'ccessive I suif'ace.qaortions of the object to the desired ptemperatur eaand depth,followedxby the quenching jetsiare usual-1y maintainedsa constantdistance Jap'art, and either thecohject may be movedmast the flames andquenching jets, r01 theefiames and quenchin'gajets .may be, moved alongEth'e ."ebject. ,FI-he progressive method is normally used inhardeningiong bearing areas, as :on lathe-bed ways, guide rails and thelike, or relatively narrow or irregular surfaces, such as ca'ms, sheaveand pulley grooves, and the like. ,In *aflfourth method, termedcombination, :a,

flatmates-art. The'cbnibihatiohmethodfis used 1' zoiaims. (class- 443principal-1'5 meaning was: dramas;

section, such as ro lis scy-linderstand shaftsthe,

object being t otatediwithin sawing or ;'group of heating iflames. andispacedrquenohing jets, while theobjec t ror mematmmm heatmefiames andquenching :iets, aiie :movedfiaxialiy of the obi ect.

This :produces A an .even .c heating ;effect, with the resuit that-e amore uniform thickness of :case can be secured. H i Ans-objectiof thisrinvention -is to provide a flame hardening machine is ea-pab1e ofuseyin hardening 2a wlarge variety;-.=of objects and partssxa's theentireaor seiectedsurfiace per; tions of cylinders, rolls, and shafts;the teeth-oi gears (spu r-., bevel, helical, and herringbone) pihions,snroclietsrwomnssand-screws; the-grooves of sheaves and Ziuiieysgtheweari-agaportions of guide-rails, tpiates discs, ringe, qbeams,channels, and other surfaces 3d manyyother articles;

. iflnother robtect of js invention isto provide afiame haixgiening a rach-ir-ie which is capableoi' arryinexouwmw 3 .6%! 1. al h9 a 03application of flame hardening, and primarily Among further objects ofthisfinvention a'r'e togproyide -a flame hardening, ,rnachine which-iscapable sv sti ianqimq n 7 more torches and associated quenching devicesat a th respectto a work chrie .lby lwhich fthe to provide'such amachinelohylhich the markpiecamay be n ounted 1; for rotation about La"vertimen smau objects such Well as, relar l t oe' bkt ie pmri a-su hajma torch adjustment deyiee eaesud a.

includes a no support; and hydraulicxdriwe arrangement for;.movi;ng the,torches and quenching devices; to provideqsuchamachine inthe torchesandzcuenohing devices ,are

r dg sliar as possib e;

ed numter includes a novel moved relatively slowly during hardening, butmay be returned to initial position, as for the next hardeningoperation, at a relatively rapid rate; and to provide such a machine inwhich the control mechanism may be mounted so as to balance the weightof the torch support and centering device.

Among additional objects of this invention are to provide attachmentsfor the machine which will enable different articles, such as bevelgears, herringbone gears or pinions, worms and the like, to be mountedwith the axis of the object horizontal or at some other angle to thevertical; to provide such attachments which may readily be attached toand mounted on the machine with a minimum of effort; and to provide atruly universal flame hardeningmachine which is operable in an efiectiveand efficient manner.

Other objects and the novel features of this invention will becomeapparent from the following description, taken in connection with theaccompanying drawings, in which:

Fig. 1 is a side elevation of a universal flame hardening machineconstructed in accordance with this invention, in position for hardeninga cylindrical object, such as a roll or shaft;

Fig; 2 is a vertical transverse section, taken through the supportingcolumn of the machine of Fig. 1, along line 2-2 thereof;

Fig. 3 is a diagram of the hydraulic system of the machine of Fig. 1;

Fig. 4 is a diagram of the oxygen and acetylene supply and controlsystem of the machine of Fi 1;

Fig. 5 is a top plan view of a novel centering device forming a part ofthe machine of Fig. 1, and taken along line 5-5 thereof;

Fig, 6 is a partial transverse vertical section, taken along line 6-45of Fig. 5;

Fig. 7 is a top plan view of a torch supporting ring and associatedparts, taken along line 1-1 of Fig. 1, and partly broken away forclarification;

Fig. 8 is a vertical section taken along line 8-8 of Fig. 7, andparticularly illustrates a torch adjustment device;

Fig. 9 is a horizontal section taken through the variable speed drivemeans, along line 9-9 of Fig. 1;

' Fig. 10 is a longitudinal vertical section taken through the articlesupport and also through a portion of the variable speed drive means,along line Ill-40 of Fig. 9;

' Fig. 11 is a diagram of the electrical circuit of the machine of Fig.1, including an automatic timer to provide additional control;

Fig. 12 is a three dimensional view of the hardening of a roller by themachine of this invention, and also illustrates an angle driveattachment for supporting the article for rotation about a horizontalaxis;

' Fig. 13 is a vertical section taken through the angle drive attachmentof Fig. 12, along line l3-l3, and also illustrates the manner in whichthe angle drive attachment is mounted on the machine and is driven;

Fig. 14 is a partial three dimensional view, illustrating the hardeningof a bevel gear by the machine of this invention, and also illustratesan attachment for mounting the gear, the gear being partly broken awayfor clarification;

' Fig. 15 is a partial side elevation illustrating the hardening of alarge spur gear by the machine of this invention;

' Fig. 16 is a partial three dimensional view il1us-.

'4 trating the hardening of a guide rail by the ma-' chine of thisinvention; and

Fig. 17 is a partial three dimensional view illustrating the spinhardening of a small pitch gear by the machine of this invention.

As shown generally in Fig. 1, the universal flame hardening machine ofthis invention may comprise an upright column C, mounted forlongitudinal adjustment along a base B, on which is also mounted drivemeans D for turning a rotating shaft Ill of a work support W and therebyrotate the article to be hardened, such as a roll or short shaft H. Thedrive means D is preferably constructed to provide adjustment of thespeed of rotation of shaft Ill, as in a manner explained later. Thecolumn C extends upwardly in a vertical direction and carries a movablesupport M for flame hardening means F, the latter being adapted to heatand quench successive portions of the surface of roll H during rotationof the roll and upward movement of the flame hardening means F. Column Calso carries an upper support U, which is adjustable to diiferentvertical positions, but normally remains stationary during eachhardening operation. Upper support U includes a novel alignment device,described in detail later, which is adapted to maintain an upper centerl2 in alignment with a lower center H, with the roll or shaft H mountedbetween the centers l2 and I3. is mounted on a face plate M, which inturn is attached to the upper end of rotating shaft H).

The movable support M is moved upwardly and downwardly by suitablemeans, such as hydraulically actuated means which includes an interiorpiston rod I5 and an exterior rod [6, connected together at their upperends by a block I1. Interior rod i5 extends centrally within column C,moving upwardly and downwardly therein, while exterior rod it movesupwardly and downwardly with a similar motion transmitted theretothrough block 57, and is guided at the lower end by a slide it adaptedto move along vertical Ways l9, formed on column C. Movable support M ismounted on exterior rod 16, while upper support U is mounted on ways I9, each being adjustable to any desired position upwardly or downwardlythereof. Upper support U is constructed, and the parts of flamehardening means F are preferably so positioned, that sufiicientclearance is obtained for hardening to the upper end of article H, aswill also be apparent from later description. Ordinarily, the uppersupport U is positioned just above the upper end of the article, asshown, but when a shaft to be hardened, for instance, is longer than canbe accommodated with upper support U in its uppermost position, uppercenter i2 is removed, and the shaft is merely extended through the uppersupport U. The alignment device of support U operates equally well inmaintaining upper center l2 or the article to be hardened in alignment,even though the latter rotates, as explained later. Mounted on theopposite side of column C from supports M and U, to counterbalance theweight of the supports M and U and the parts mounted thereon, is acontrol housing H, in which is installed the majority of the controlvalves, regulators, electrical and hydraulic control mechanism, andassociated parts. The housing H may be divided into a lower section 8and an upper section 9, the former being adapted to enclose theelectrical control parts, and the latter the oxygen, acetylene, andhydraulic control parts. The housing H may, of course, be unitary, butthe Lower center [3 diesel terates iie'ifnito lower secti'oii tssuos'equ a d it of an eh eat as pump; he lessene buttons "2i" "and 2!for g-the new or or den-ills re;

theorem button 2: or chari r to" mp 22'', which is-lit curing the 'tlwhienuie t I set, in

section ll include shyass handle and associated iter the lay-pass valveregulating l ily use fluid and thereby control- Y of upward movement ofihov ala'le support ll/l the ilaine hardening means carrie'd thereby; acontrol wheel 25 we hydraulic bypass"valve, which is normally closed; ahydra. q'eiessure' es 1%; an lene pressure en pressu in'dlcating the cryice The ylehe f valve 30, and the my .eedle valve 3!, disposed in anaccessible position for adjustm'ent, when desired. also, an electricaloutlet receptacle 32 may be provided on lower section aror attachment ofMore. le'ading'to a portable control switch.

A. control handle 33 of a four-way hydraulic control valve also extendsfrom the control housing H, in position to be actuated. stops $4 35',mounted mop-posed position on aeontrolrod 36. Control 'ro'd tii eiitends alongside column C, the lower end of the control rod beingreceived in a hole provided in a boss 3'! adjacent theoot tom of columnThe upper end of the control rod extends through a bracket 38 at thupper endof column 3, aspring 39 being provided above bracket 38 tomaintain the control rod ina nor mal position. upper or lower end oftraverse by engagement of slide it with stops til; ill, it" or lt, whichare adjustable in position alongcontrol rod Stops it and it are usedas'the limit stops for operations involving traverse of an articlehaving a length such as the shaft ll shown in Fig; 1, but stops as" andit may also be used. Thus, the traverse may be between stops ill andlil. shown, or between stops ill and llif or 510', in the latterinstance stop 43') being adjusted. to a pivotal position facing controlhousing H, for instance, to prevent engagement Toy slide iii, stop fillalso being similarly adjusted when desired.

Or, the traverse may be between stops 4D or fill or between stops ill"and f lii'f. In general, stops t9 and lfi' are provided above stops 3and 35 to facilitate adjustment of the machine, obviating the removal ofease st'ops lfl or W, below the central stops 3t 3&3, when one or bothlimits of traverse life along the upper portion of rod 36.

In the position shown in Fig. l, hydraulicham die 33 'is in-a center orneutral position, to start the machineupwardly, control handles? passagetlii'o ;li a metering on: s to nee le.

Control rod 3315 moved at the sees it so e m at the co der one 10d 8'5will so Ved upwafdl Then anal"e eratlonsuurme use of-thls 1i1a= chineare sufficiently long, so that manual move"- more era-1e control handlee3 at the beginning ,but itw'lllb'e on:

re competely automatic op-era traverse 1s tioi' s entirely feasible.

"tini' simultaneously or prior to end or up"- "'e," by alimit "switch Mmounted at a'tiiile adapted to befenga'ged by a stop attached'to controlrod 35;. Thus, when the cr end'or traverse is reached, and theeontrolactuated. to shut off the'he-ating flames.

The drive means is also provided withex terlo controls, including a pushbutton switch it, for starting "and stopping the drive means motor;three gear 'a'djustmentlevers as and ll, respectively; and a clutchoperating handle tilwhioh also is shifted to provide additional speedselection. As will be explained in detail later, gear shifting leversdty it, and M, and clutch handle All are'moved' to diflerentpositions,in accordance with the speed of rotation of work shaft i0 desired. It issufficient for the present to state that thespe'eds which may beselected extend over asg'reater range than required for known flamehardening requirements. "in general, the required rate of rotation ofthe article is determined by its diameter, since the perlphoral speed isusually the determining factor. Thus, for articles'having a relativelysmall diameter, a greater rate of rotation is normally required than forlarger articles.

For hardening cylindrical articles, not excessive in diameter, thecolumn C is left in the position of Fi'g. l, but for hardening otherarticles, thecolumn 0 maybe adjusted to a different 130- sition alongbase B, as in Fig; 12, or even removed therefrom, as in Fig. 15. For"such ad"- justment, and as shown in Figs. 1, 2, 12 and 16, the column 0is provided at its lower end with flanges-Ell, adapted to slidealongways 5| on base I5 is provided with apiston 5a, which divides apressure tube or cylinder 55 intoan upper chamber 56 and a lower chamber-57, so that appropriate hydraulic pressure in chamber 57 will causetheflame hardening means F to move upwardly; and inchamb'er-ES,downwardly. Cylinder' 5% preferably has relatively exact dimensions toaccommodate'piston 54, being formed of drawn tubi'ngfloi th like, and;as'in Fig. 2, is connected in a fluid tight manner at opposite endswithafi again therein? sto ping the traverse movement;

be turned" on" auto-r of oolu'nin G and havingan actu roe. ismovedupwardlvlimit switch will be.

upper cap 58 and a lower cap 59 of column 0, the former being providedwith a gland 50 and packing BI to accommodate and provide a seal for rodI5. Since cylinder 55 is mounted within column C, which may be formed bycasting or the like, the latter need not have nearly as accuratedimensions, and machining expenses are reduced. In addition, a fluidcompartment or reservoir 52 is provided within column outside cylinder55. As in Figs. 1 and 2, the hydraulic fluid is transmitted to and fromchambers 55 and 51 by pipes 53 and 64, communicating respectivelythrough a connection 65 in upper cap 58 and a connecting passage 65 inlower cap 59.

The hydraulic system, as indicated previously, is illustrateddiagrammatically in Fig. 3, and includes a pump 56 supplied with fluidfrom reservoir 62, as through an intake line 61, provided with astrainer 68. Pump 56 supplies fluid at a predetermined pressure to afour-Way valve 59, through a pump discharge or pressure line I5, excesspressure to valve 69 being prevented by a relief valve II, installed inpump discharge line III and connected by a relief pipe I2 with pumpintake line 51. also be connected to pump discharge line II! at reliefvalve 'II, as shown. Four-way valve 59 is conventlonal, being movablebyhandle 33 to three diilerent positions, a central or neutral position,an upper or downward movement position, and a lower or upward movementposition. When handle 35 is in the central or neutral position, pressureline '15 is connected with a drain pipe 13, leading to reservoir 62, sothat the entire fluid flow supplied by pump 57 passes to reservoir 52,as indicated by the dot-dash arrow Id. The remaining connections ofvalve 59 are sealed, so that piston 54 remains in position in column C,and there is no movement of exterior rod I and movable support M. Whenthe handle 33 is moved downwardly, i. e., for upward movement of piston55, pressure line Iii is connected with pipe 54, through a regulatingline l5 containing a regulator valve I6, controlled by handle 23, tosupply fluid under pressure to lower chamber 51, the flow of fluid inlines and 55 being in the direction of the solid arrows 'I'I. Thus,piston 54 will tend to be moved upwardl in the direction of solid arrow11'. At the same time, fluid forced out of upper chamber 55 passesthrough pipe 83, in the direction of the solid arrow ll", to four-wayvalve 59, and thence through drain pipe l3 for discharge to reservoir52, the flow through drain pipe I3 being always in the direction ofclotted arrow Id. The speed of upward travel of piston 54 and movablesupport M is determined by the setting of regulator valve I6, which maybe set for any position from fully closedat which the rate of upwardtravel will be zeroto a maximum rate of travel.

For quick adjustment to a maximum rate of upward travel, or to permitregulating valve I5 to remain at a specific adjustment, a normallyclosed globe valve l8, controlled by handle and installed in a by-passline I9, may be opened. By-pass globe valve E8, or other manuallyoperated valve, may be used in bringing the quenching jets up rapidly atthe end of upward traverse, after the heating flames are shut offautomatically; in bringing the quench rapidly into position afterheating in a spin hardening operation; and for other purposes, such aswhen adjusting the speed of upward traverse manually, as when testingthe position of stops 34, 35, 40, 40", 40", and/or 43.

Hydraulic pressure gage 26 may When handle 33 of four-way valve 691smoved to an upper position, i. e., for downward movement of piston 54,pressure line 70 is connected with pipe 63, the flow to upper chamber 56being in the direction of dotted arrow and the movement of piston 54being in the direction of dotted arrow At the same time, fluid forcedout of lower chamber 5! will pass through pipe 64, in the direction ofdotted arrow 80', through a check valve BI in a line 82 by-passingregulating valve I5, and thence to four-way valve 59. In this positionof four-way valve 69, line I5 is connected with drain line I3, the flowthrough drain line I3 to reservoir 62 being always in the direction ofdotted arrow I4, as indicated previously.

The oxygen and acetylene supply means, including the parts installed incontrol housing H, may be constructed as illustrated diagrammatically inFig. 4. Thus, an oxygen supply line 84 and an acetylene line 85 may beprovided with shut oflf valves 38, regulator valves 81, and pressuregages 88, these being located exteriorly of the housing H. Insidehousing H, the oxygen and acetylene lines are equipped with solenoidoperated valves 89 and 55, respectively, while a metering orifice SI isprovided in oxygen line 84. Oxygen gages 28 and 29 and acetylene gage 21are visible from the exterior of housing H, as indicated previously.Oxygen line 84 leads to a manifold 92, supplying oxygen to the flamehardening means F (described in greater detail later) through oxygenvalves 3 I, and the acetylene supply line 35 leads to a manifold 93,similarly supplying acetylene to the flame'hardening means l F throughacetylene valves 30.

The upper support U includes a novel alignment device, as illustrated inFigs. 1, 5, and 6. The support U includes a bracket formed with a ring55 at its outer end and at its inner end provided with clamps 57 forattachment to ways I9 of column C. Bracket 95 is also provided with anaperture 93 adjacent ways I 9 to accommodate exterior rod I5. Ring 95 isprovided with a series of equally spaced, inwardly extending projections99, such as three, while a handwheel IIIIl is mounted on ring 95 forrotational movement, being adapted to be clamped in any specificposition by clamps IN. A radial guide-way 552, for a slide I55, ismounted on each projection 59, slides I53 being moved inwardly oroutwardly by turning handwheel I55. The slides I53 are actuated througha suitable linkage which may consist of an outer link I54, pivotallyattached at opposite ends to handwheel l 00 and a center link I55, andan inner link I06, pivotally attached at opposite ends to center linkI55 and slide I03. Center link I05 is pivotally mounted centrallythereof on a stud I07, in turn mounted on projection 99. As will beevident, rotation of handwheel I50 will move slides 99 inwardly oroutwardly, dependent upon the direction of rotation, whether clockwiseor counter-clockwise, respectively, as viewed in Fig. 5.

Each slide I03 is interiorly threaded to receive an adjusting screw I58,adapted to be locked in position by a lock nut N39, and carrying at itsinner end a roller IIEi. As inFig. 6, the upper center I2 may be mountedin a collar III which is adapted to rotate on rollers I Ill, duringrotation of the article being treated. The inner ends of rollers It'llare preferably adjusted closer to the shank of collar I I I than asshown in Fig. 6, as the spacing has been exaggerated for clarity ofillustration, the preferred clearance being such that the collar III andupper center I2 are mainsheaves Stained in accurate alignment, but thefriction travel of movable support M may be treated, by first hardeningone half of the shaft, and then reversing the shaft for hardening of theother half.

The movable support M, on which maybe mounted the flame hardening meansF, as illustrated in Figs. 1, 7, and 8, may comprise a bracket H3encircling rod it and clamped thereto in a suitable manner as by a setscrew, and provided with a mounting ring I I t. The flame hardeningmeans F includes one or more blowpipes, each having a head H5 providedwithsuitable heating flame orifices, as in removable tips ii 5 whichpermit a variation in the flame pattern, and

Inountedon the inner end of a barrel I H. A combustible mixture ofoxygen and acetylene is supplied to the barrel by a hose or flexibleconduit I 18, and cooling water is supplied from a hose or flexibleconduit 1 it, being circulated through the barrel and to the head. Waterfor quenching the heated surface may be discharged from suitable outletsin blowpipe heads H5, but preferably is discharged through ouench heads12! having inclined inner faces I and correspondingly inclined quenchoutlets, for discharging the quenching liquid at an. angle away from theheating flames. Each quench head I2!) is mounted at the inner end of atube l2i, quenching liquid being supplied through a hose I22. Quenchhead H28 is adjustably attached to blowpipe head I I5, as by a wing nutand bolt I23, the bolt depending from blowpipe head H5 and disposed in alongitudinal slot in quench head 12c. Both barrel N5 of each blowpipeand corresponding tube 12! of the quenching device are slidably mountedin a block iM, which is attached to ring M, as by a bolt or the like,ring ll-t preferably being provided with a series of holes equal innumher to the maximum number of mounting blocks {2.4 to be attachedthereto. nects each blowpipe barrel 1 it with an adjusting screw 5 whichis adapted to threadedly engage a split nut 12? which is mounted forsliding movement in a slot it at the upper end of block H24 and whichmay be moved into and. out of engagement with screw I25 by a screw H9.

As will be evident, the quench tube l2! slides in block EM whenever anadjustment of the blowpipe barrel H? is made. By lifting split nut H21,a quick, adjustment of the blowpipe head may be made to a desiredgeneral position, while a finer adjustment may be made by screw 526after split nut 12'! is lowered. The blowpipe heads H5 and. quenchingheads H8 may be adjusted from a position relatively close to the centerof ring 1 M, as in Fig. 7, to accommodate a shaft or the like ofrelatively small diameter, or to positions further outwardly, as in Fig.1, to accommodate a shaft or roll of medium diameter, or still furtheroutwardly to an extreme outward position, to accommodate a roll having adiameter almost as great as that of ring H4. Also, only one blowpipe maybe mounted on ring I; it. as in Fig. 16, and the, number may be, variedin accordancewith the-work to be treated.

A collar we con- Directingthe quenching jets at an angle away from theheating flames tends to produce less interference with the heatingflames, and also permits a slight soaking period to produce a more evenheating effect. If desired, provision may be made for adjustment of aquench head Hill to a different vertical position with respect to thecorresponding blowpipe head lib, but radial adjustment is usually allthat necessary, particularly since the angle of the quenching jets issuch that radial movement of a quench head I20 will cause the spacingbetween the points of impingement of the heating flames and quenchingjets to be varied vertically on the work. The blowpipe heads"! [5 may berhomboidal in shape, so that two heads may be placedrelative'ly clcsetogether, as in Fig. 12, and the "heating e'fiect of the 'flam'es willt'end to overlap, thus reducing the tendency for striations in thehardness pattern to be produced, particularly when hardening by theprogressive method. I

The oxy-acetylene mixture is formed inaconventional manner, as in mixersi 30 mounted on brackets I35, as in Fig. 7, and supplied from valves 38and 3! with the respective gases by hoses I32, as in Figs. 4 and 7. Eachruixerlt il is connected by a pipe L33 with a header its, mountedbeneath ring us, as in Fig. 8, each header 134 being merely a multipleoutlet block for supplying the combustible mixture to any desired numberof blowpipes through. hoses lit, there "being any'desired numberofheaders in accordance with the number of blowpipes. Thus, one headerwill supply three blowpipes, but lesswhen convenient for posi tioningpurposes, i. e., there is preferably at least one header on each side ofring Hi When there are blowpipes on each side of the ring, with outletsnot in use being plugged, as in Fig. 7. A ring-shaped cooling waterheader I35, and a similar but preferably larger ring-shaped quenchingwater header 236, may be mounted beneath ring lit by clamps or othersuitable means.

The drive means D, as illustrated in Figs. 1;

9, and '10, is installed principally within a housing I31 having aremovable cover, and includes a motor I38 mounted, as in Fig. 9, on agear casing I39. Motor E33 drives a high speed shaft Mil through a pairof v -belts i4! extending around motor pulley M2 and shaft pulley Ms. Atriple cluster gear [M is splined on high speed shaft its, and is movedby a fort; ltdactuated by handle ifijt'o high, intermediate, and lowspeed positions. Cluster gear M l thereby adapted to engage a lowsinglegear Hit, or either set of teeth of a dual high and intermediategear Hi'i, gears I46 and Ml being keyed on a countershaft I48 andproviding a first stage of speed change. A second stage of speed changeis provided by single gears its and use, also keyed on countershaft itsand adapted to selectively engage the two sets of teeth of a dual gearidi, splined on a second countershait I52 and shifted by a fork 253, inturn actuated by handle To provide a third stage or speed change, atriple cluster gear E54 is also splined on second countershaft I52, andis adapted to be moved selectively to different positions by a fork 55,in turn actuated by handle :37. Triple gear IE4 selectively engageseither set of teeth of a dual gear Hit or a single gear I52, each keyedto an output shaft 158.

To insure smoothness of operation, forks M", tilt and may be constructedto slide along a guide rod 159, while highspeed shaft M8, each ofthe=countershafts M8 and 152, and out put shaft I58, may run in ballbearings I58 and I59. Also, each handle 45, 46, 41 and 48, as shown forhandle 15, may be provided with a spring pressed detent IBI, adapted toengage notches I52 in the outside of easing I39, or, if desired, incover I31, to maintain the forks I45, I53 and I55 and the gearsshiftable thereby, in desired positions.

A fourth and optional stage of speed change may be provided by a jawclutch I65, splined on a driveshaft I65 of Fig. 10 and shiftable bymovement of handle 48, operating through a fork I 65, into alternativeengagement with a direct drive jaw I61 or a speed reduction jaw I68, toprovide High and Low speeds, as indicated in Fig. 9. Direct drive jawI51 is keyed to output shaft I58, while speed reduction jaw I55 isattached to and rotates with a worm gear I69, driven continuously by aworm I10, at a reduced speed from output shaft I58. The drive fromoutput shaft I 58 to worm I10 includes a sprocket pinion I 1| keyed tooutput shaft I58 and driving a sprocket gear I12 through a chain I13; acountershaft I14, to one end of which sprocket gear I12 is keyed; andbevel gears I15 and I15, keyed to the end of shaft I14 and shaft I16 ofworm I10, respectively. Worm gear I69 is thereby rotated continuously ata slow speed, and when jaw clutch I64 is in direct drive position-i. e.,engaging jaw I'I- shaft I65 rotates within worm gear I69. Bevel gearsI15 may be of different sizes, as shown. to provide additional speedreduction, although they may be made the same size, and the reductionbetween shaft I58 and worm I may be accomplished entirely between shaftI58 and countershaft I14, as by the relative sizes of pinion I1I andsprocket I12, for which a spur pin ion and gear may also be substituted.

The parts comprising the fourth stage of speed change are mountedprincipally in a housing I11, in which sleeve bearings I18 may beprovided for sprocket gear shaft I14 and worm shaft I16, as in Fig. 9,although ball bearings may be utilized, if desired. Also, as in Fig. 10,a pair of sleeve bearings I19 may be provided for drive shaft I65, onebeing mounted in worm gear I69 and the other in housing I11, whilesleeve thrust bearings I80 may be provided for worm gear I69, each beingmounted in hous" ing I11.

The drive to work support W is completed by a bevel pinion I8I keyed tothe end of drive shaft I65, as in Fig. 10, and meshing with a bevel gearI82 keyed to the lower end of shaft Ii! of the work support. Worksupport W includes a housing I83, having a cap I84 provided with avertical sleeve bearing I85 and packing gland I86 for shaft Ill. Becauseof the weighti. e., of shaft I0, bevel gear I82, and the work beingtreated-a ball thrust bearing I81 is preferably provided at the lowerend of shaft III. Face plate I4 may be threadedly secured to the upperend of shaft II], the latter being provided with projecting jaws I88 fordriving certain attachments, as hereinafter described, while lowercenter I3 merely restson face plate I4, and does not engage jaws I88.Cap I84 is also provided with radially spaced lands I89, alternatingwith the attaching bolts and utilized in supporting an angle driveattachment A of Fig. 12, or the like, in a manner explained later.

As will be evident, to select the desired speed of rotation for shaftIII of worksupport W, levers 45 to 41, inclusive, and clutch handle 48are-moved to various positions. It will be noted that with clutch handle&5 moved to the right, or direct drive position, one complete series ofspeeds, i. e., High, may be obtained through positioning of levers 55 to41, while another complete series of slower speeds, i. e., Low, may beobtained by moving clutch handle :38 to the left, or reduction driveposition. Also, when clutch handle 55 is in a center or neutralposition, as in Figs. 9 and 10, clutch I54 is disengaged and face plateit and/or shaft It may be readily rotated, during preliminary or workpositioning operations. As will be evident, the permutations of speedspossible with the different positions of the levers indicated in Fig. 9as positions 1, 2 and 3 for lever 41, positions 4 and 5 for lever 46,and positions A, B and C for lever 45-together with the two differentpositions of clutch handle 58, provide a range of speeds whichaccommodate practically any article to be hardened; It will beunderstood, of course, that other gearing systems may be used, and alsothat a variable speed drive may be connected to motor I35, so that aninfinite number of speed variations may be obtained.

As an example of the various speeds of rotation of shaft I9 by a machineconstructed in accordance with this invention, which of course does notrepresent all possible examples, the following table is given. In thistable, the posltions given are those indicated in Fig. 9.

RI 1TM Lever Position gg M .007 3 4 .4 5.1 .009 3 4 o 3.5 .013 3 4 B 5.5.026 1 4 A 11 .053 1 4 o 14 .047 1 4 B 20 .055 2 4 A 23 .057 2 4 o 29.051 3 5 A 35 .095 2 4 B 41 .103 a 5 o 44 .145 3 5 B 53 .296 1 5 .4 128.375 1 5 o 162 .531 1 5 B 229 .604 2 5 A 251 .757 2 5 c 531 1.082 2 5 B458 From the above table, it will be evident that, in the position shownin Fig. 9, i. e., 2-4-3, with clutch handle 45 in the low position, thespeed of shaft II! will be 0.095 R. P. M., while with handle 48 in thehigh position, the speed of shaft II] will be 41 R. P. M. As will beevident, there is a speed range of .007 R. P. M. to 468 R. P. M., whichis suificient to accommodate small shafts or large rolls, and also tospin harden small pitch gears.

For the various hardening operations, suitable electrical controlmechanism may be used, such as illustrated diagrammatically in Fig. 11.This circuit may be supplied with suitable current, such as 1l0-volt, 60cycle, by wires ISI and I92, the former of which may be connected to aterminal I93 of a two-pole magnetic contactor or relay R, and the latterof which may be connected to a terminal I94 r of a timer T, with a wireI95 connecting terminal I84 with a terminal I96 of contactor R.

Through wires I91 and I98, leading respectively from terminals I93 andI95, line current is supplied to the windings I99 of oxygen and Iacetylene solenoid control valves 89 and 98, under 15 a small pitch gear231 is mounted for rotation on face plate M; a plurality of torches,such as six, are grouped about the gear, for directing the heatingflames from heads H against the teeth of the gear 23'l; and the gear isrotated at a relatively rapid rate, such as 100 to 200 R. P. M. Thetorch mounting posts lZ l are disposed in spaced positions about ringH4, and

the torch heads H5 are moved inwardly to a desired position spaced fromthe gear, so that the inner cones of the heating flames are about /8 in.or so from the ends of the gear teeth. The movable support M, in thiscase, remains stationary, and the quench is not directed against thegear until after the heating flames are turned off. The teeth may beheated for a matter of thirty seconds to one minute, for instance, andthe heating flames turned off automatically. Or, if it is desired toturn the heating flames on" manually, the timer T may be set, asindicated previously, so that control of the solenoid Valves 89 and 9tis manual, but the timer will turn off the incandescent lamp 22 at theend of a pretermined period of time. After heating, the

quench may be provided by moving the movable support M upwardly asufiicient distance so that the quenching jets will impinge against theheated gear teeth, at the end of the predetermined heating period. Thisis readily accomplished by opening globe valve it of Fig. 3 throughhandle 25 of Fig. 1, to cause the quenching jets to move quickly intoposition. Stop 4%, or any other stop, may be set to stop the quenchingiets at the desired vertical nosition.

Indicator timing, with lamp 22, may also be used in other hardeningoperations, particularly at the start of the hardening of a shaft orroll by the combination method or of a fiat surface by the progressivemethod. Preferably, what may be termed a standing start is utilized,wherein the heating flames are applied to the lower end of the surfaceportion to be hardened, until the surface has reached substantially thecritical temperature, whereupon the movable support M is startedupwardly, and the heating flames are caused to traverse successiveportions of the surface. During such a standing start, the initialsurface portion is normally relatively cold, as compared to the criticaltemperature, but as the initial portion is heated substantially to thecritical temperature, the flames traverse upwardly and the heat willtend to run ahead, as it were, to preheat surface portions above. Thus,the time necessary to heat any specific surface portion that has beenpreheated in such a manner is much less than if such surface portionwere heated from a cold condition. Sufficient information has beenobtained regarding the times necessary for a standing start for specificsizes of shafts and rolls, and with a specified number of blowpipe headsor tips, as normally measured by gas consumption, that the amount oftime spent during the standing start for most articles to be hardened isreadily ascertained. Also, in the case of a material or article withwhich no previous experience has been had, a very slight amount ofexperimentation will be sufiicient to determine the best period of timefor a standing start. Thus, if the time required for the standing startis twenty seconds, for instance, the timer T may be set for the periodof twenty secends, but leg ZIEI of selector switch 209 placed againstmanual contact 2! i, so that the timer T will not turn off the oxygenand acetylene at the end of the twenty second period, but will merelyturn off the lamp 22'. When one of the starting buttons is pushed, themotor 221 of the timer will begin to turn, and also the solenoid valves89 and 98 will be opened. As soon as the predetermined period has ended,such as the above period of twenty seconds, the lamp 22 will be turnedoff, and this will indicate to the operator that the desired standingstart period has expired, and the operator then will be able to startthe upward movement of movable support M and the flame hardening means Fcarried thereby, with assurance thatthe standing start period has beenproper and the desired hardness will be obtained.

The above manner of controlling the start of heating may be utilized inconnection with the hardening of shafts or rolls, as illustrated in Fig.1, and also in the hardening of other types of articles, such as theperipheral surface 238 of a roller 239, as in Fig. 12; the hardening ofa tooth 24!] of a bevel gear 25!, as in Fig. 14; the hardening of atooth 242 of a large spur gear 2&3, as in Fig. 15; and the hardening ofa bearing surface 244 of a guide rail 245, as in Fig. 16. In eachinstance, the timer T may be set for the standing start time, and theupward movement of traverse of the flame hardening means F started assoon as lamp 22 goes out. It will be understood, of course, that in lieuof lamp 22', a buzzer, horn, or other signal may be utilized, whichlatter may also be connected in the circuit so as to be turned on at theend of the predetermined time period, rather than being on during theperiod.

As shown in Fig. 12, roller 239 is rotated in the direction indicatedabout a horizontal axis, being mounted on an angle drive attachment A,the roller being attached to a face plate 25E! which is mounted onthreads 25! at the outer end of a horizontal shaft 252, shown in Fig.13.

, The angle drive attachment A includes a housing 253, installed on thework support W of Fig. 1 in the manner shown in Fig. 13, and ineluding avertical shaft 256 having jaws 255 at its lower end engaging jaws I88 ofshaft It, and a set of bevel gears 256 for transmitting the rotativemovement of shaft 254 to shaft 252.

The angle drive attachment A rests on cap I84 of work support W, housing253 being provided with a flange 25? which rests on lands I89 formedatop cap it, lands 889 being shown also in Fig. 10. The angle driveattachment A may be attached to cap we in a suitable manner, as by boltsor cap screws. The upper end of shaft I 0 and packing gland I 86 extendwithin housing 253, while bearings 253 and 258' are provided for shaft254, housing 253 being provided with interior webs 259 and 259' formounting bearings 258. Shaft 252, in turn, rotates in bearings 266 and26!), mounted in the upper end of housing 253. The flame hardening meansF is mounted on an alternative movable support M, as in Fig. 12, withone or more blowpipe heads H 5 disposed side by side and sufiicient innumber to cover the Width of surface 288, the ends of heads I I 5 beingin spaced relation to the surface 238 to be hardened. The quenchingheads I20 are disposed immediately below the blowpipe heads H5, anddirect jets of quenching water against the suc cessive heated surfaceportions. The surface 238 is hardened during one revolution of theroller 2355, so that the gearing of drive means D is set for arelatively slow speed of rotation, such as a to produce a peripheralspeed of surface 238 of 6 to 8 inches per minute. I

aeeavaa "The? movable. support. M! comprises?- an -inner bar: or link262, adj ustablymounted atcits inner endion' rodilli'hyset screws or:thelike; and p vided at itsxouter end with a plate 263 on which the"inner end" of an=outer bar or link. 264 is piv oted. Links 262 and 264mayhave any suitable cross-sectionalshape; such as inverted channels;and are adapted to be adjusted to any desired lateralposition, such asthat shown in Fig. 12, or further outwardly: or inwardl'ytoaccommodatework ofvariousdimensions. Outer'link 264 isprovided with aslide 265', adjustable by an adjusting screwZBl, to adjust thepositionof a blowpipe rack", consistingof' a lower'box 266 and an upperbar 261'. Box Z'iidmay beopen, as shown, the sidewalls-thereof beingprovidedwith relatively deep slots 268, each adapted to receive a quenchtube I21, and generally arcuate slots 269, each adapted to receive ablowpipe barrel H1; each slot 268 being, of course; connected with and"having a common verticalcenterline with a s1ot269'." Bar 2Ei1is providedwith arouate-slo'ts 216, each adapted to engage the topof a bl'owpipebarrel H1, and bar 261' is adapted to be clamped thereagainst, asbyclampingbolts 211;

When hardening a surface such as surface 238 of roller 239' by'theprogressive method, the flamehardening means F and the support M remainstationary, beingset in the desired position: However, whenhardeningarticles in which the flame hardening means F is moved, the movablesupport M is also moved, in the manner previously described.

The name hardening meansl is supplied with a combustible mixture ofgases, cooling water and'flquenching water in a manner similar to: thatvpreviously described. Thus, an oxyacetylenemixture may be suppliedthrough 110585 folds 212 and 213 being'mounted beneath outer link 264 ofsupport M"in a suitable manner, as

by clamping to a plate 214 weldedto the under side oflink 264. As shown,outlets of com bustibl'e mixture" headers I34 not in use are blockedoff, as-by caps, and manifo1ds212 and 2131 are similarly provided with aplurality of outlets; with those not in me being blocked off;

In hardening teeth. 240 of" bevel gear 24!, as illustrated in Fig. 14,the hardening operation iscarried out with the gear mounted in astationary position, but with the lowermost tooth 240 thereof disposedvertically and at the lower peripheryof the gear. Special gear hardeningheads 216 having suitable outlets for discharing heating flames followedby quenching jets against the opppositesides of a tooth are mountedfor'upward. movement with respect to the tooth, on either movablesupport M or M. Gearhardening heads 216, also shown in Fig. 15, maybeconstructed in the manner set forth in U. S. Patent No. $224,006 toRoger Day.

Hoses I32 11st justable'canglesupport A" is'monnted onixface plate. 14,which isturned to a suitable position, and'rthen remains. stationary.The support A includes a spindlet. 211, atthe outer end ofxan arm218,gear 241 beingclamped to spindle 211 and arm 218 being mounted for.pivotal adjustment on the upper end of a vertical standard 219; thelatter having a base Ziiil clamped to faceplate M. A circular dial 28fhaving angle graduations 2B2 around-asuitable portion of its periphery,is welded or otherwise suitably attached to'arm 218, graduations 282being adapted to register with an indicating mark 283 on standard 219 toindicate the angular position of the axis of spind1e211 with respect tothe horizontal Pivotaladjustment of. arm 218 may be: obtained byloosening a clamping bolt 2%, movingspindle. 211 to the angular positiondesired, and then re-tightening bolt 284.

The heads 216 are preferably maintained with a: constant; distance,therebetvveen, and any variation, in heating effect due to the taperingsides: of the toothy-may be compensated'for'by adjustment in. the" speedof movement of the heads. It will be understood, of course, that duringthe hardening of the teeth of bevel gear 2 the gear remains stationaryin position during the hardening of each tooth. Therefore, shaft H1ofjwork-support W is not rotated, and drive means D is not utilizedduring such hardening; However, as; soon as one tooth has been hardened,and after: the gear hardening heads haveg'been returned to a positionbeneath the lowermost tooth; the gear 24]. is turned for a distance of:one tooth on spindle 211, to move the; next tooth into i the lowermostor hardening position.

Gearzhardening heads 2160f Fig. also may be mounted on movable support Min a manner similar. to that illustrated in Fig. 15,:wherein the" teeth242. of a relatively large spur gear 243' are'being-hardened; Hub 285 ofgear 243 is mounted directly" on face plate M of work sup'portW, and.drivemeans D is not utilized, except that-handle is moved to a neutralposition, so that jaw clutch I64 will be in a neutral position, such asin theposition of Fig. 9, and indexing-of gear 2'43 will be relativelyeasy. As in thecase of bevel gear 241 of Fig. 14, the gear. hardeningheads 216 of Fig. 15 are moved upwardly" past opposite sidesv of thetooth 2412 being hardened, and then returned to a lower position beneaththe teeth, whereupon gear. 2 is; indexed orturned, to present the nexttooth for treatment.

As in Fig. 15, the gear hardening heads 216 may be mounted on a specialsupport 28*, such as a short section of: I-beam,'and clamped" to oneedge of ring H4 of movable support 'M. Although not all of theconnections are shown, mixer Hill and header I34 are attached to themovable support as before, the flexible hoses and conduits for supplyinga combustible mixture of gases and cooling and quenching water to theheads 215 being installed in a conventional manner.

As will be evident from Fig. 12, the alternative movable supportlvfimaybe utilized in positioning the gear hardening heads closer tothe-columndC whenzthe teeth of a gear smaller than'the' relatively largespur gear 243 of Fig; 15 are being hardened, but, as in. Fig. 15, forrelatively" large gears, it may be desirable to remove column C frombase B, and place it on the floor at one end of: the base. As indicatedpreviously, the weight of control housing'I-I balances the weight of themovablesupport M and upper center U (the latter not showing in Fig. 15),so that there is little possibility of the column becoming overbalanced.Also, since the gear hardening heads 216 do not touch anything, then thecolumn C may be safely placed directly on a level floor, or speciallyinstalled bed plate or other level surface, without bolting or clampingwhich, however, may be done if desired.

During the hardening of gear teeth, as in Figs. 14 and 15, the heatingflames may be turned off automatically at the end of traverse, and theheads 216 automatically returned to a lower position, in the mannerdescribed pre-v viously. Also, a standing start may be utilized, in themanner previously described, wherein the automatic timer is set only tocontrol indicatim light 22 of Figs. 1 and 11.

Such a standing start may also be utilized in the hardening of thebearing surface 244 of guide rail 245, as in Fig. 16. The guide rail 245may be placed on end, atop face plate M- (which remains stationary) sothat the bearing surface 2 54 is vertical, and the flame hardening meansF is moved upwardly in the direction of the arrow, as shown. Dependingupon the width of surface 244, any desired number of blowpipes may beutilized, only one blowpipe head H5 provided with a row of tips H6,adapted to direct heating flames across the width of surface 244, beingnecessary in the instance shown, although additional blowpipes and/ortips may be utilized when necessary. The blowpipe of Fig. 16 is mountedin a block I24, clamped to ring H4 of movable support M, and theoxy-acetylene mixture, cooling water, and quenching water are suppliedas described previously.

The ring 1 M of the movable support M is positioned to encircle theguide rail 245, and the blowpipe is mounted to extend inwardly towardthe surface 244, column C being adjusted to a relatively close inwardposition, as shown. It will be understood, of course, that for largerguide rails and the like, the blowpipe or blowpipes may be placed inother positions on the movable support M, or the movable support M,shown in Fig. 12, may be utilized in positioning such blowpipes. Theshaft I ll of work support W is, of course, not rotated since the guiderail 245 remains sta-- tionary, and if more than one guide rail of .asimilar nature is to be hardened, each guide rail hardened is replacedby the next guide rail to be hardened.

The heating flames may be turned off automatically, or manually, at theupper end of traverse of the flame hardening means F. Also, duringhardening, in case heat tends to travel up along the surface, as towardthe upper end of traverse, at a faster rate than along lower portions ofthe surface, the upward movement of support M and flame hardening meansF may be increased, as through by-pass valve control 23, of Figs. 1 and3, in the manner previously described.

In each of the operations carried out by the machine of this invention,the surface to be hardened is placed in a vertical position, andhardening begins at the lower end and proceeds upwardly. This isadvantageous, since hardening in an upward direction is more readilycontrolled, and more uniform results are produced.

As will be evident, the universal flame hardening machine of thisinvention fulfills to a marked degree the :requirements and"objectshereinbefore setforth. ,A large'variety of objects and partsdiffering both in size and shape, may be hardened by the machine of thisinvention. Also, any desiredfispeed'of hardening may be used; while thespeed range for parts to be rotated is sufficient to accommodatesubstantially any size of object. The column C, on one side of which ismounted the housing H, and on the op-' posite side of which are mountedthe movable and stationary supports and other parts, is readily adjustedto different positions, and even may be, moved entirely off the base. Asindicated previously, when moved off the base, the column still remainsbalanced, so that the possibility of its tipping over or the like isavoided.

The flame hardening machine of this invention,- while primarily adaptedto perform the 'combination and progressive methods, may also beutilized in spot and spin hardening. The num ber of torches which may bemounted on the supports M or- M may vary from one to a relatively largenumber, and these torches may be grouped around a roller shaft which isrotated, around a gear whose teeth are to be hardened, or in a positionfor hardening a surface placed vertically.- Also, other types ofblowpipes, such as the special gear hardening heads shown in Figs. 14and- 15, may be utilized. In hardening elongated parts to be rotated,such as shafts and rolls, the centering device of this invention insuresaccurate positioning and maintenance of alignment during rotation.'Various phases of the hardening operation may be made automatic, suchas the distance traversed, the time of heating for a spin hardeningoperation, and the time of shut-off of the heating flame. Also, .thetime, ing circuit of this invention may be set to indicate to theoperator when a predetermined time has elapsed, which is particularlyuseful for a standing start. The tor-ch adjustment device of thisinvention also permits quick and accurate positioning of the torches,either grouped about a part to be hardened having a circular crosssection, or with the torches extendinginwardlyor outwardly from thesupport toward the surface, to be hardened. The hydraulic drive for the;movable support is easily set and readily controlled, and both long andshort objects may be hardened with ease and facility. The speed range ofthe hydraulic control is particularly, adapted to operations wherein thesurface to be hardened is in a vertical position, as the flamehardeningmeans may be moved upwardly at a; relatively slow rate, but returneddownwardly, to the initial position, at a relatively rapid rate. The useof the space in the interior of column C, around tube 55 for piston 54,as a reservoir for hydraulic fluid, both simplifies constructionand addscompactness.

The angle drive attachment and the adjustable angle support furtherenhance the universality of the machine of this invention. By the angledrive attachment, parts such as rollers, sheaves and the like, may beplaced for rotation about a horizontal axis, while with the adjustableangle support, parts such as bevel gears or the like, may be placed atany desired angle to-the horizontal. These attachments insure that thesurface to be hardened can be quickly and easily placed in verticalposition.

Although certain specific embodiments of this invention have beendescribed, it will be understood that other embodiments may exist, and

that various changes may be made, all without 1

